O Level Biology Practical 2020 Answers 90%
Answer: Water moved into potato cells by osmosis down a water potential gradient, making cells turgid (increase in length/mass).
If you want, I can convert this into a printable revision sheet, produce a sample 10‑question mock practical paper with marking scheme, or adapt it to a specific exam board format. Which would you like?
The Investigation of Photosynthesis in Elodea Plants
It was a sunny day in May 2020, and biology students from a local school were heading to the laboratory to conduct their O-level biology practical exam. The topic of the practical was the investigation of photosynthesis in Elodea plants.
The students had been preparing for weeks, revising the concepts of photosynthesis, and practicing their experimental skills. As they entered the laboratory, they were greeted by the familiar sight of Elodea plants, microscopes, and various equipment needed for the experiment.
The task was to investigate how light intensity affects the rate of photosynthesis in Elodea plants. The students were required to design and conduct an experiment to measure the effect of different light intensities on the rate of photosynthesis.
The Experiment
Each student set up their own experiment, using a similar method: o level biology practical 2020 answers
The Results
As the students collected their data, they began to notice a trend. The closer the lamp was to the plant, the more oxygen was produced. This made sense, as higher light intensities provide more energy for photosynthesis to occur.
When they plotted their results on a graph, they saw a positive correlation between light intensity and the rate of photosynthesis. However, they also noticed that at very high light intensities, the rate of photosynthesis seemed to level off.
The Answers
Now, let's imagine some possible answers to common questions that might be asked in the O-level biology practical exam:
Answer: To investigate how light intensity affects the rate of photosynthesis in Elodea plants.
Answer: As light intensity increases, the rate of photosynthesis also increases, but may level off at very high light intensities. Answer: Water moved into potato cells by osmosis
Answer: Elodea plants are used as a model organism to investigate photosynthesis. They produce oxygen as a byproduct of photosynthesis, which can be measured and used to estimate the rate of photosynthesis.
Answer: By repeating the experiment multiple times, using similar equipment and methods, and controlling variables such as temperature and light source.
Of course, these are just sample answers, and actual answers may vary depending on the specific questions and requirements of the exam.
List the apparatus and materials needed for the experiment:
Expected Answer:
Describe the procedure for the experiment:
Context: Practical papers usually require you to observe a specimen (often a flower, fruit, or preserved item) and produce a biological drawing. The Results As the students collected their data,
Common Student Errors in 2020:
| Test | Observation | Conclusion | | :--- | :--- | :--- | | Benedict’s | Blue (no change) | Reducing sugar absent | | Iodine | Blue-black | Starch present | | Biuret | Blue | Protein absent | | Ethanol | Clear | Fat/lipid absent |
Final identification: Starch solution (or starch suspension).
The O Level Biology Practical 2020 answers reveal a clear pattern: examiners reward precision in method (step-by-step), accurate scientific vocabulary (plasmolysis, not "shrunk"), and well-annotated drawings.
Final actionable advice:
Good luck with your O Level Biology revision. Master the 2020 practical answers, and you will be ready for any food test, osmosis, or enzyme question that comes your way.
Need more help? Leave a comment below with the specific variant (e.g., 5090/33/O/N/20) and question number, and we will provide the exact mark scheme answer.